- McMahon or MacMahon (UK: , US: ; older Irish orthography: Mac Mathghamhna; reformed Irish orthography: Mac Mathúna) is an Irish surname.
- The McMahon–Hussein Correspondence is a series of letters that were exchanged during World War I in which the United Kingdom government agreed to recognize Arab independence after the war in
- The McMahon Line is the demarcation line between the Tibetan region of China and the North-east region of India proposed by British colonial administrator Henry McMahon at the 1914 Simla Conv
- The McMahon family is a prominent Irish American family, primarily known for their involvement in the professional wrestling business.
- McMahon Stadium is a Canadian football stadium in Calgary, Alberta. The stadium is owned by the University of Calgary and operated by the McMahon Stadium Society.